1 files changed, 319 insertions, 0 deletions
diff --git a/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/Iterator.cpp b/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/Iterator.cpp
new file mode 100644
index 000000000000..ac0f24603dd9
--- /dev/null
+++ b/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/Iterator.cpp
@@ -0,0 +1,319 @@
+//=== Iterator.cpp - Common functions for iterator checkers. -------*- C++ -*-//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Defines common functions to be used by the itertor checkers .
+//
+//===----------------------------------------------------------------------===//
+
+#include "Iterator.h"
+
+namespace clang {
+namespace ento {
+namespace iterator {
+
+bool isIteratorType(const QualType &Type) {
+  if (Type->isPointerType())
+    return true;
+
+  const auto *CRD = Type->getUnqualifiedDesugaredType()->getAsCXXRecordDecl();
+  return isIterator(CRD);
+}
+
+bool isIterator(const CXXRecordDecl *CRD) {
+  if (!CRD)
+    return false;
+
+  const auto Name = CRD->getName();
+  if (!(Name.endswith_lower("iterator") || Name.endswith_lower("iter") ||
+        Name.endswith_lower("it")))
+    return false;
+
+  bool HasCopyCtor = false, HasCopyAssign = true, HasDtor = false,
+       HasPreIncrOp = false, HasPostIncrOp = false, HasDerefOp = false;
+  for (const auto *Method : CRD->methods()) {
+    if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(Method)) {
+      if (Ctor->isCopyConstructor()) {
+        HasCopyCtor = !Ctor->isDeleted() && Ctor->getAccess() == AS_public;
+      }
+      continue;
+    }
+    if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(Method)) {
+      HasDtor = !Dtor->isDeleted() && Dtor->getAccess() == AS_public;
+      continue;
+    }
+    if (Method->isCopyAssignmentOperator()) {
+      HasCopyAssign = !Method->isDeleted() && Method->getAccess() == AS_public;
+      continue;
+    }
+    if (!Method->isOverloadedOperator())
+      continue;
+    const auto OPK = Method->getOverloadedOperator();
+    if (OPK == OO_PlusPlus) {
+      HasPreIncrOp = HasPreIncrOp || (Method->getNumParams() == 0);
+      HasPostIncrOp = HasPostIncrOp || (Method->getNumParams() == 1);
+      continue;
+    }
+    if (OPK == OO_Star) {
+      HasDerefOp = (Method->getNumParams() == 0);
+      continue;
+    }
+  }
+
+  return HasCopyCtor && HasCopyAssign && HasDtor && HasPreIncrOp &&
+         HasPostIncrOp && HasDerefOp;
+}
+
+bool isComparisonOperator(OverloadedOperatorKind OK) {
+  return OK == OO_EqualEqual || OK == OO_ExclaimEqual || OK == OO_Less ||
+         OK == OO_LessEqual || OK == OO_Greater || OK == OO_GreaterEqual;
+}
+
+bool isInsertCall(const FunctionDecl *Func) {
+  const auto *IdInfo = Func->getIdentifier();
+  if (!IdInfo)
+    return false;
+  if (Func->getNumParams() < 2 || Func->getNumParams() > 3)
+    return false;
+  if (!isIteratorType(Func->getParamDecl(0)->getType()))
+    return false;
+  return IdInfo->getName() == "insert";
+}
+
+bool isEmplaceCall(const FunctionDecl *Func) {
+  const auto *IdInfo = Func->getIdentifier();
+  if (!IdInfo)
+    return false;
+  if (Func->getNumParams() < 2)
+    return false;
+  if (!isIteratorType(Func->getParamDecl(0)->getType()))
+    return false;
+  return IdInfo->getName() == "emplace";
+}
+
+bool isEraseCall(const FunctionDecl *Func) {
+  const auto *IdInfo = Func->getIdentifier();
+  if (!IdInfo)
+    return false;
+  if (Func->getNumParams() < 1 || Func->getNumParams() > 2)
+    return false;
+  if (!isIteratorType(Func->getParamDecl(0)->getType()))
+    return false;
+  if (Func->getNumParams() == 2 &&
+      !isIteratorType(Func->getParamDecl(1)->getType()))
+    return false;
+  return IdInfo->getName() == "erase";
+}
+
+bool isEraseAfterCall(const FunctionDecl *Func) {
+  const auto *IdInfo = Func->getIdentifier();
+  if (!IdInfo)
+    return false;
+  if (Func->getNumParams() < 1 || Func->getNumParams() > 2)
+    return false;
+  if (!isIteratorType(Func->getParamDecl(0)->getType()))
+    return false;
+  if (Func->getNumParams() == 2 &&
+      !isIteratorType(Func->getParamDecl(1)->getType()))
+    return false;
+  return IdInfo->getName() == "erase_after";
+}
+
+bool isAccessOperator(OverloadedOperatorKind OK) {
+  return isDereferenceOperator(OK) || isIncrementOperator(OK) ||
+         isDecrementOperator(OK) || isRandomIncrOrDecrOperator(OK);
+}
+
+bool isAccessOperator(UnaryOperatorKind OK) {
+  return isDereferenceOperator(OK) || isIncrementOperator(OK) ||
+         isDecrementOperator(OK);
+}
+
+bool isAccessOperator(BinaryOperatorKind OK) {
+  return isDereferenceOperator(OK) || isRandomIncrOrDecrOperator(OK);
+}
+
+bool isDereferenceOperator(OverloadedOperatorKind OK) {
+  return OK == OO_Star || OK == OO_Arrow || OK == OO_ArrowStar ||
+         OK == OO_Subscript;
+}
+
+bool isDereferenceOperator(UnaryOperatorKind OK) {
+  return OK == UO_Deref;
+}
+
+bool isDereferenceOperator(BinaryOperatorKind OK) {
+  return OK == BO_PtrMemI;
+}
+
+bool isIncrementOperator(OverloadedOperatorKind OK) {
+  return OK == OO_PlusPlus;
+}
+
+bool isIncrementOperator(UnaryOperatorKind OK) {
+  return OK == UO_PreInc || OK == UO_PostInc;
+}
+
+bool isDecrementOperator(OverloadedOperatorKind OK) {
+  return OK == OO_MinusMinus;
+}
+
+bool isDecrementOperator(UnaryOperatorKind OK) {
+  return OK == UO_PreDec || OK == UO_PostDec;
+}
+
+bool isRandomIncrOrDecrOperator(OverloadedOperatorKind OK) {
+  return OK == OO_Plus || OK == OO_PlusEqual || OK == OO_Minus ||
+         OK == OO_MinusEqual;
+}
+
+bool isRandomIncrOrDecrOperator(BinaryOperatorKind OK) {
+  return OK == BO_Add || OK == BO_AddAssign ||
+         OK == BO_Sub || OK == BO_SubAssign;
+}
+
+const ContainerData *getContainerData(ProgramStateRef State,
+                                      const MemRegion *Cont) {
+  return State->get<ContainerMap>(Cont);
+}
+
+const IteratorPosition *getIteratorPosition(ProgramStateRef State,
+                                            const SVal &Val) {
+  if (auto Reg = Val.getAsRegion()) {
+    Reg = Reg->getMostDerivedObjectRegion();
+    return State->get<IteratorRegionMap>(Reg);
+  } else if (const auto Sym = Val.getAsSymbol()) {
+    return State->get<IteratorSymbolMap>(Sym);
+  } else if (const auto LCVal = Val.getAs<nonloc::LazyCompoundVal>()) {
+    return State->get<IteratorRegionMap>(LCVal->getRegion());
+  }
+  return nullptr;
+}
+
+ProgramStateRef setIteratorPosition(ProgramStateRef State, const SVal &Val,
+                                    const IteratorPosition &Pos) {
+  if (auto Reg = Val.getAsRegion()) {
+    Reg = Reg->getMostDerivedObjectRegion();
+    return State->set<IteratorRegionMap>(Reg, Pos);
+  } else if (const auto Sym = Val.getAsSymbol()) {
+    return State->set<IteratorSymbolMap>(Sym, Pos);
+  } else if (const auto LCVal = Val.getAs<nonloc::LazyCompoundVal>()) {
+    return State->set<IteratorRegionMap>(LCVal->getRegion(), Pos);
+  }
+  return nullptr;
+}
+
+ProgramStateRef createIteratorPosition(ProgramStateRef State, const SVal &Val,
+                                       const MemRegion *Cont, const Stmt* S,
+                                       const LocationContext *LCtx,
+                                       unsigned blockCount) {
+  auto &StateMgr = State->getStateManager();
+  auto &SymMgr = StateMgr.getSymbolManager();
+  auto &ACtx = StateMgr.getContext();
+
+  auto Sym = SymMgr.conjureSymbol(S, LCtx, ACtx.LongTy, blockCount);
+  State = assumeNoOverflow(State, Sym, 4);
+  return setIteratorPosition(State, Val,
+                             IteratorPosition::getPosition(Cont, Sym));
+}
+
+ProgramStateRef advancePosition(ProgramStateRef State, const SVal &Iter,
+                                OverloadedOperatorKind Op,
+                                const SVal &Distance) {
+  const auto *Pos = getIteratorPosition(State, Iter);
+  if (!Pos)
+    return nullptr;
+
+  auto &SymMgr = State->getStateManager().getSymbolManager();
+  auto &SVB = State->getStateManager().getSValBuilder();
+  auto &BVF = State->getStateManager().getBasicVals();
+
+  assert ((Op == OO_Plus || Op == OO_PlusEqual ||
+           Op == OO_Minus || Op == OO_MinusEqual) &&
+          "Advance operator must be one of +, -, += and -=.");
+  auto BinOp = (Op == OO_Plus || Op == OO_PlusEqual) ? BO_Add : BO_Sub;
+  const auto IntDistOp = Distance.getAs<nonloc::ConcreteInt>();
+  if (!IntDistOp)
+    return nullptr;
+
+  // For concrete integers we can calculate the new position
+  nonloc::ConcreteInt IntDist = *IntDistOp;
+
+  if (IntDist.getValue().isNegative()) {
+    IntDist = nonloc::ConcreteInt(BVF.getValue(-IntDist.getValue()));
+    BinOp = (BinOp == BO_Add) ? BO_Sub : BO_Add;
+  }
+  const auto NewPos =
+    Pos->setTo(SVB.evalBinOp(State, BinOp,
+                             nonloc::SymbolVal(Pos->getOffset()),
+                             IntDist, SymMgr.getType(Pos->getOffset()))
+               .getAsSymbol());
+  return setIteratorPosition(State, Iter, NewPos);
+}
+
+// This function tells the analyzer's engine that symbols produced by our
+// checker, most notably iterator positions, are relatively small.
+// A distance between items in the container should not be very large.
+// By assuming that it is within around 1/8 of the address space,
+// we can help the analyzer perform operations on these symbols
+// without being afraid of integer overflows.
+// FIXME: Should we provide it as an API, so that all checkers could use it?
+ProgramStateRef assumeNoOverflow(ProgramStateRef State, SymbolRef Sym,
+                                 long Scale) {
+  SValBuilder &SVB = State->getStateManager().getSValBuilder();
+  BasicValueFactory &BV = SVB.getBasicValueFactory();
+
+  QualType T = Sym->getType();
+  assert(T->isSignedIntegerOrEnumerationType());
+  APSIntType AT = BV.getAPSIntType(T);
+
+  ProgramStateRef NewState = State;
+
+  llvm::APSInt Max = AT.getMaxValue() / AT.getValue(Scale);
+  SVal IsCappedFromAbove =
+      SVB.evalBinOpNN(State, BO_LE, nonloc::SymbolVal(Sym),
+                      nonloc::ConcreteInt(Max), SVB.getConditionType());
+  if (auto DV = IsCappedFromAbove.getAs<DefinedSVal>()) {
+    NewState = NewState->assume(*DV, true);
+    if (!NewState)
+      return State;
+  }
+
+  llvm::APSInt Min = -Max;
+  SVal IsCappedFromBelow =
+      SVB.evalBinOpNN(State, BO_GE, nonloc::SymbolVal(Sym),
+                      nonloc::ConcreteInt(Min), SVB.getConditionType());
+  if (auto DV = IsCappedFromBelow.getAs<DefinedSVal>()) {
+    NewState = NewState->assume(*DV, true);
+    if (!NewState)
+      return State;
+  }
+
+  return NewState;
+}
+
+bool compare(ProgramStateRef State, SymbolRef Sym1, SymbolRef Sym2,
+             BinaryOperator::Opcode Opc) {
+  return compare(State, nonloc::SymbolVal(Sym1), nonloc::SymbolVal(Sym2), Opc);
+}
+
+bool compare(ProgramStateRef State, NonLoc NL1, NonLoc NL2,
+             BinaryOperator::Opcode Opc) {
+  auto &SVB = State->getStateManager().getSValBuilder();
+
+  const auto comparison =
+    SVB.evalBinOp(State, Opc, NL1, NL2, SVB.getConditionType());
+
+  assert(comparison.getAs<DefinedSVal>() &&
+    "Symbol comparison must be a `DefinedSVal`");
+
+  return !State->assume(comparison.castAs<DefinedSVal>(), false);
+}
+
+} // namespace iterator
+} // namespace ento
+} // namespace clang